In September, Reykjavik typically sees daytime highs of 10.3°C and overnight lows around 5.2°C. Compared to the annual average high of 6.9°C, September runs +3.5°C.
September in Reykjavik averages a daytime high of 10.3°C and an overnight low of 5.2°C.
September runs +3.5°C compared to Reykjavik's annual average high of 6.9°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 10.3°C and cooler evenings around 5.2°C.